I tend to prefer the binders that do up with zippers or velcro rather than stretching over my head, so I put them on lying on my back, let gravity take them where they will (which hasn't been anywhere near "up" since I was maybe 18 and they'd reached their full adult size, which was way more droopy than perky), and then adjust them a little in every direction. Some goes up, some goes down, some goes sideways...I try not to cram it all in one direction to avoid stretching the skin too much, especially "down" (woman boobs are bad enough, but I really don't want to encourage worse granny boobs than I've already got!), though I think it'd be flatter if I did squish them more down and more sideways. The binders I've got won't let me put too much under my armpits before it oozes out the holes, though.
